1. Field of the Invention
The present invention relates to a perpendicular magnetic recording head that records information on a recording medium by applying a magnetic field in a direction perpendicular to a medium facing surface.
2. Description of the Related Art
A perpendicular magnetic recording head has a laminated structure in which a return yoke layer is provided on a medium facing surface that faces a recording medium with a nonmagnetic insulating layer disposed on a main magnetic pole layer. The main magnetic pole layer and the return yoke layer are magnetically connected to each other at a portion disposed closer to the starting point of the height direction than the medium facing surface. A coil layer is buried in the nonmagnetic insulating layer so as to apply a recording magnetic field to the main magnetic pole layer and the return yoke layer. In a magnetic head having such a configuration, when current is supplied to the coil layer, a recording magnetic field is induced between the main magnetic pole layer and the return yoke layer. The recording magnetic field is incident perpendicularly from the medium facing surface of the main magnetic pole layer to a hard film of the recording medium and returns to the return yoke layer after passing a soft film of the recording medium. Accordingly, information is recorded on a region of the recording medium opposed to the main magnetic pole layer (see JP-A-2005-122831 (Patent Document 1).
The return yoke layer and a shield layer of the perpendicular magnetic recording head are typically formed of a substantially rectangular thin-film magnetic body. When an external magnetic field is applied in the height direction, magnetic flux is concentrated on edges of the thin film. At this time, the height directional magnetization component becomes dominant, causing rewriting (edge write phenomenon) of previously recorded information. That is, in order to suppress the magnetic field attributable to the edge write phenomenon, it is necessary to decrease the height directional component of the magnetic field generated from the edges of the return yoke layer or the shield layer.